Control switch for synchronized clutch mechanisms



Dec, 29, 1942. c. w. SEWELL 2,306,645

CONTROL SWITCH FOR SYNCHRONIZED CLUTCH MECHANISMS Filed July 1, 1940 3 Sheets-Sheet 1 Dec. 29, 1942. c. w. SEW E LL 2,306,645

. CONTROL SWITCH FOR SYNCHRONIZED CLUTCH MECHANISMS Filed July 1, 1940 M s Sheets-Sheet 2 fzwanZZr 62ml"; W 62206]! Dec. 29, 1942. c. w. SEWELL CONTROL SWITCH FOR SYNCHRONI ZED CLUTCH MECHANISMS Filed July 1, 1940 I 3 Sheets-Sheet I rwanr am mzwzz Patented Dec. 29, 1942 CONTROL SWITCH 'FOR SYNCHRONIZED CLUTCH MECHANISMS Charles William Sewell, Staines, England, as-

signor to Lagonda Motors Limited, Staines,

Middlcsex, England Application July 1, 1940, Serial No. 343,507 In Great Britain October 21, 1939 5 Claims.

This invention relates mainly to electric switches, our main object being to provide a satisfactory form of compact switch which will close temporarily when a pivoted actuating member is moved in a given direction, the return movement of the actuating member leaving the switch inoperative.

Such a switch is required in the case of a change-speed mechanism of the kind disclosed in the specification accompanying co-pending patent application No. 306,571, filed November 28, 1939.

According to the present invention, the switch includes a rocker biassed in one direction against a stop, and a pivoted actuating member coacting with a spring member carried by the rocker. The parts are arranged so that on movement of the actuating member in one direction the line of force on an eye or other engaged portion of the spring member is to one side of the pivotal axis of the rocker, whilst further movement of the actuating member flexes the spring member and carries the actuating member past the said engaged portion, thereby first turning and then releasing the rocker and thus effecting engagement and subsequent release of the switch. Subsequent full movement of the actuating member in the other direction leaves the rocker inoperativei. e., the line of force on the said engaged portion is then to the other side of the pivotal axis of the rocker.

The invention further involves the combina tion with a change-speed mechanism according to the patent specification above-mentioned, of a switch as aforesaid, the switch-actuating member being connected to be operable automatically on movement of the gear shift lever or other main control.

According to a further feature of the invention,

in the combination above-mentioned, and in which there is a double-acting slidable synchronizing device, use is made of a pair of oppositelydisposed switches as aforesaid having a common actuating member between them, whereby when the synchronizing device is moved fully in one direction the. appropriate coil alone is temporarily energized and in the other direction only the other coil.

In the accompanying sheets of drawings:

Figure 1 is a fragmentary sectional elevation showing a change-speed mechanism having the top and next speed introduced by means of dog clutches and electromagnetic synchronizing clutches, for the control of which latter the switch of the invention is eminently satisfactory;

- mechanism;

Figure 2 is an elevation, to a smaller scale, of another form of gear-box arranged to give three forward speeds, having electromagnetic synchronizing means for each forward speed which can be controlled by the switch of the invention;

Figure 3 is a sectional elevation, to'a larger scale, of the device of Figure 2 for introducing third speed (direct drive) and second speed;

Figure 4 is a sectional elevation, also to the larger scale, of the device of Figure 2 for introducing first speed;

Figure 5 is a sectional elevation of part of one form of actuating means for the gearing of Figures 2 to 4;

Figure 6 is a cross-section taken on the line VIVI of Figure 5;

Figure 7 is a plan, with the cover removed, of a pair of switch mechanisms, according to the invention, for use in connection with the change-speed mechanism of Figures 2 to 4;

Figure 8 is a front elevational view of the switch mechanisms,

Figure 9 is a side elevation of the actuating member for these switch mechanisms; and

Figure 10 is an enlarged plan of part of one of the switch mechanisms.

In the construction of Figure 1, l6 represents the tail end of a driving shaft journalled in bearings Illa in a gear casing ll. .Fast on the driving shaft is a gear I2 in permanent mesh with a gear l3 fast on a layshaft l4. I5is a gear fast on the layshaft and in permanent mesh with a gear l6 free on a driven shaft H.

A double-acting slidable device is mounted as usual on the driven shaft between two externally-toothed dog clutch elements l8, IQ of magnetic material. One of these (I8) is fast with the driving shaft and the. other (I9) is free upon the driven shaft, being fast with the free gear l6 thereon. This device includes a carrier for two electro-magnets 2|, 22 which are adapted to coact, respectively, with the adjacent flat radial faces of the dog clutch elements aforesaid. The carrier comprises a hub portion 23 slidably splined upon the driven shaft, and a central radially-extending flange portion 24 against which the two electro-magnets 2!, 22 rest, being rotatably mounted thereon and endwise held by spring rings 230. Each of the electro-mag nets comprises an outwardly-facing, channelsection annulus of magnetic material with an appropriate coil 25 disposed in the interior thereof.

The outer periphery of the flange portion 24 showing also the third switch of the carrier has a sliding and driving engagement with a slidable, double-ended, dog clutch sleeve 26 which in its extreme positions can engage with one or other of the dog clutch elements [8, [9. The dog clutch sleeve also has a sliding and driving engagement with the two electromagnets 2|, 22, thus restricting them from rotating on the carrier.

In addition, a spring-loaded ball 2'! mounted in the carrier serves for centralizing the carrier with respect to the dog clutch sleeve, and the latter has a peripheral groove 28 engaged by a striking fork 29. Current for the two coils can be brought along leads 3! provided in the interior of the driven shaft, the leads emerging through a radial hole therein into the interior of the flange of the carrier, whence they are connected to the respective coils.

Assuming that the parts of the mechanism are in the neutral position shown, movement of the change-speed lever in a direction to introduce, say, top speed, causes the operation of appropriate switch contacts (as hereinafter described) whereby a circuit for the associated coil 25 is closed, whilst at the same time the dog clutch sleeve and synchronizing device are moved slightly in the appropriate direction as a whole-to the left in Figure 1 for top speed." The electromagnetic attraction resulting from the energization of the coil tends to cause the electromagnet 23 to revolve in synohronism with the adjacent dog clutch element l8, and this electro-magnet 2|, being free to rotate on the carrier except for the sliding and driving connection between it and the dog clutch sleeve 26 and between the latter and the carrier, introduces a frictional resistance which is operative for discouraging sliding movement of the dog clutch sleeve until synchronization has been reached. Thereupon the further axial movement of the dog clutch sleeve can take place relatively freely; and before engagement between the dog clutch elements occurs the circuit is preferably broken at the said contacts, thus allowing the actual engagement of the dogs to take place freely.

The contacts are arranged so that, when changing down from top speed, the movement of the dog clutch sleeve into the neutral position does not complete a circuit for either coil 25.

The operation of moving from neutral to the speed below top speed is similar in all respects to that described.

In the construction shown in Figures 2 to 4, again represents a driving shaft, l2 a gear fast thereon and in permanent mesh with a gear 13 fast on a layshaft l4, and I5 is a gear fast on the layshaft and in permanent mesh with a gear l6 free on the driven shaft l'l. Figure 2, in addition, shows a gear 32 fast on the driven shaft and in permanent mesh with a gear 33 free on the layshaft for first speed. Moreover, in each case, the synchronizing device includes an electromagnetic clutching means disposed eX teriorly of the slidable dog clutch element. Thus, the synchronizing device for introducing top or second speed includes a slidable dog clutch element 34 which is slidably splined at 35 upon the driven shaft and internally engaged by a cross pin 36 working in longitudinal slots 3! in the driven shaft. The cross pin is engaged by a rod 38 disposed in the interior of the shaft and carrying a cross pin 39 which works in slots 4| in the shaft and is connected externally of the shaft to a grooved ring 42 engaged with a striker fork 43. In the present instance the dog clutch elements 64, 45, which are fast with the gears l2 and i8, respectively, are formed integrally therewith, and secured thereto are flanges 46, 41 of magnetic material for coacting with the interposed electromagnetic member 48 having in its interior the two exciting coils 49.

Current for the coils can be brought in by slip rings 5| which are respectively connected to the coils, the other ends of the latter being earthed to the electro-magnetic member 48 which should be formed of a material having a small residual magnetism. The slip rings are insulated from the electro-magnet by an insulating ring 52. The electro-magnetic ring 48 is freely journalled and slidably mounted on bronze rings 53 mounted on the positive clutch elements 44, 45. In addition, the electro-magnetic member 48 has a frictional sliding and driving connection with the slidable dog clutch element. which connection is indicated diagrammatically at 54.

In the case of first speed the parts are arranged in a substantially similar manner, except that here the electro-magnetic member 55 is a single-acting one journalled partly on a bronze ring 56 carried by the positive clutch element 51 which is fast with the gear 33 and, on the other side of the slidable positive clutch element 58, on the layshaft. The slidable positive clutch element, which is slidingly splined at 59 on the layshaft and has a frictional comiectiorr 6| with the electromagnetic member 55, has a cross pin 62 working in slots 63 in the layshaft and connected by a rod 64 leading to the end of the layshaft Where it can be actuated by an appropriate mechanism. The elements 54 and El act in the manner of splines and may be replaced by splines if desired.

It is believed that the manner in which first. second or third speed can be introduced, on the sliding of the appropriate dog clutch element, will readily be understood from the description given in connection with Figure 1. For the manner in which the slidable dog clutch elements may be actuated attention may be directed to the following description, in which reference is made to Figures 5 to 10.

Figures 5 and 6 show one end of a flexible actuating shaft 65 disposed in a flexible casing 66, the shaft end being connected to a rod 61 which is slidably and rotatively mounted in a casing 68. The rod has a groove 67a and holes 6Tb to coaot with a spring-pressed locating plunger in known manner. The manner in which the other end of the flexible shaft 65 is connected to be operated by the gearshift means such that the rod 61 may be slid axially or rotated forms no part of the present invention but will readily be apparent to those skilled in the art.

Fast on the inner end of the rod 61 is an arm 69 terminating with a ball portion which is engaged in an eye 1| on an arm 12 secured on a rod 1'3 by a dowel pin 74. Fast on the rod 13 is a finger l5. 16, TI and 18 represent selector forks, 16 being that for third and second speed, 11 that for first speed and 18 that for the reverse drive. Thus, the selector fork 15 is connected in any convenient manner with the striker fork 43. and the selector fork 11 with the rod 64. The reverse drive gearing, which may be of any ordinary kind, is not shown for the sake of simplicity.

The selector forks are aligned with one another in a usual manner to coaot with the finger 15. Figure 5 shows the finger engaged with the selector fork ll. If the rod 61 be rotated, due to the engagement of the arm 69 with the arm H the rod 13 will be correspondingly raised or lowered, according to the direction of rotation of the rod 61, to bring the finger 15 into engagement with one or other of the other selector forks I6, 78. On the other hand, if the rod 61 e Pulled or pushed the rod 13 will be rotated, thus causing axial movement of whichever selector fork is engaged by the finger I5.

In order to prevent movement of any selector fork while it is not engaged by the finger 15, use is made of dogs 19, 80 which arefreely mounted though endwise held upon the rod 13 by a shoulder or pin carried thereby and have a sliding keyed connection at 8! with the stationary casing 82. The drawings show the dogs respectively engaged with the selector forks 16, 18.

Movement of the rod 13 upwardly from the position shown will cause the lower dog 19 to coact with. both the selector'forks 11, 18. Movement of the rod I3 downwardly will bring the upper dog 80 into active co-operation with both the selector forks I6, 11.

The switch in this instance, which is disposed in the casing 82a, comprises two oppositely-disposed switching mechanisms 83, 84 for third and second speeds, respectively, and another switch mechanism 85 for first speed arranged alongside the switch mechanism 83, and a single actuating member 86 is provided for all the switch mechanisms. This includes a V-ended insulating block 81 on a strip which is secured to the upper end of the rod 13.

Each switching mechanism includes a rocker 9! pivotally mounted on a pin 92, a spring blade 23 being secured to the rocker and at one end 94 to a stationary part, whilst its free end 95 engages a stop pin 95. The free end carries a contact 81 which can co-operate with an adjustable stationary contact 98. Also secured to the rocker is a curved guide 99, and between the guide and the rocker is secured a spring blade terminating with an eye NH. The eye Hll lies in proximity to the V-end of the insulating block of the actuating member 86 when this is in the appropriate coacting positionsee, for example, Figure 7. The resiliency of the spring blade biasses it against the curved guide as shown.

It will now be observed that rotation of the actuating member 85 in one direction will cause the V-end of the block to engage the adjacent eye, the line of force passing to the contact side of the pivotal axis of the rocker. thus turning the rocker about its fulcrum pin and closing the contacts 1 91, 98. Th s completes a circuit for the appropriate coil. Further movement of the actuating member, which is fast on the rod 13, isthereupon prevented by the frictional engagement between the electromagnet and the slidable dog clutch element, which prevents movement of the latter until synchronism has been reached. On synchronism being reached, however, the actuating member 86 can be rotated further in the same direction, to flex the spring blade 93, and on passing the eye the rocker moves to open the switch contacts under the bias of the spring 93, thus de-energizing the previously-excited coil. At the same time the slidable dog clutch sleeve can be moved fully in the appropriate direction to engage the coacting dog clutch element.

Movement of the actuating member 86 in the other direction, on the rotation of the rod 13, will bring the V-end of the actuating member against the adjacent side of the eye. Such engagement r752 pulls upon the eye relatively to the rocker fulcrum in a manner to maintain the switch contacts open, i,' e., the line of force on the eye passes to the other side (remote from the contacts) of the pivotal axis of the rocker. Thus, the actuating member 86 can be returned to the neutral position without the switch contacts becoming closed.

It will be obvious that axial movement of the shaft I3, to bring the arm out of engagement with the selector fork l1 and into engagement with the selector fork 16, will move the actuating member from a position adjacent the switch mechanism into the position shown in Figure 7 in which the actuating member is disposed substantially between the two eyes of the switch mechanisms 83, 84, and vice versa.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

1. An electric switch comprising a pivoted rocker, switch contacts adapted to be closed and opened by movement of the rocker about its pivot, a stop member, means biasing the rocker to its inoperative position against said stop member, an actuating member movable in a path adjacent said pivoted rocker, an abutment disposed in the path of said movable actuating member, a resilient member connecting the abutment to the rocker at a point spaced a subs-tantial distance from the rocker pivot, said actuating member engaging said abutment and moving past the abutment when the actuating member is moved in one direction, the line of force from the actuating member through the abutment and resilient connecting member being in a direction to move the rocker away from the stop member to close the switch contacts, said actuating member during its return movement in the opposite direction engaging the abutment and moving past the abutment, the line of force from the actuating member through the abutment and re silient connecting member on the return movement of the actuating member being in a direction to urge the rocker against the stop member to maintain theopen position of the contacts,

said resilient connecting member comprising a leaf spring normally urging the abutment into the path of movement of the actuating member, and said abutment member comprising an eyelet formed by bending the end portion of the leaf spring upon itself.

2. An electric switch comprising a pivoted rocker, switch contacts adapted to be closed and opened by movement of the rocker about its pivot, a stop member, means biasing the rocker to its inoperative position against said stop member, anactuating member movable in a path adjacent said pivoted rocker, an abutment disposed in the path of said movable actuating member, a resilient member connecting the abutment to the rocker at a point spaced a substantial distance from the rocker pivot, said actuating member engaging said abutment and moving pas-t the abutment when the actuating member is moved in one direction, the line of force from the actuating member through the abutment and resilient connecting member 'being in a direction to move the rocker away from the stop member to close the switch contacts, said actuating member during its return movement in the opposite direction engaging the abutment and moving past the abutment, the line of force from the actuating member through the abutment and resilient connecting member on the return movement of the actuating member being in a direction to urge the rocker against the stop member to maintain the open position of the contacts, a curved guide secured to said rocker at a point spaced a substantial distance from the rocker pivot, said guide extending along said rocker towards its pivot end and curving away from the rocker, said resilient connecting member comprising a leaf spring normally urging the abutment into the path of movement of the actuating member, said left spring extending between the rocker and curved guide and being biased against the curved portion of said guide.

3. An electric sWitch comprising a support, a rocker pivoted to said support, a stop member carried by the support, a leaf spring secured to the support and secured to the rocker at a point spaced from the rocker pivot, said spring being biased against said stop member, a switch contact carried by said spring and rocker assembly and movable therewith, a stationary switch contact carried by the support in proximity to but normally spaced from said movable contact, said contacts being closed and opened by movement of said rocker about its pivot, an actuating member movable in a path adjacent said rocker, and a second leaf spring carried by said rocker assembly and extending into the path of said actuating member, said actuating member engaging said second leaf spring and moving past said spring when the actuating member is moved in one direction, theline of force from the actuating member through the second leaf spring being in a direction to move the rocker assembly away from the stop member to close the switch contacts, said actuating member during its return movement in the opposite direction engaging the second leaf spring and moving past said spring, the line of force from the actuating member through the spring on the return movement of the actuating member being in a direction to urge the rocker assembly against the stop member to maintain the open position of the contacts.

4. An electric switch comprising a support, a rocker pivoted to said support, a stop member carried by the support, a leaf spring secured to the support and secured to the rocker at a point spaced from the rocker pivot, said spring being biased against said stop member, a switch contact carried by said spring and rocker assembly and movable therewith, a stationary switch contact carried by the support in proximity to but normally spaced from said movable contact, said contacts being closed and opened by movement of said rocker about its pivot, an actuating member movable in a path adjacent said rocker, and

a second leaf spring carried by said rocker assembly and extending into the path of said actuating member, said actuating member engaging said second leaf spring and moving past said spring when the actuating member is moved in one direction, the line of force from the actuating member through the second leaf spring being in a direction to move the rocker assembly away from th stop member to close th switch contacts, said actuating member during its return movement in the opposite direction engaging the second leaf spring and moving past said spring, the line of force from the actuating member through the spring on the return movement of the actuating member being in a direction to urge the rocker assembly against the stop member to maintain the open position of the contacts, said second leaf spring having its end bent upon itself to form an eyelet to engage the actuating member.

5. An electric switch comprising a support, a rocker pivoted to said support, a stop member carried by the support, a leaf spring secured to the support and secured to the rocker at a point spaced from the rocker pivot, said spring being biased against said stop member, a switch contact carried by said spring and rocker assembly and movable therewith, a stationary switch contact carried by the support in proximity to but normally spaced from said movable contact, said contacts being closed and opened by movement of said rocker about its pivot, an actuating member movable in a path adjacent said rocker, and a second leaf spring carried by said rocker assembly and extending into the path of said actuating member, said actuating member engaging said second leaf spring and moving past said spring when the actuating member is moved in one direction, the line of force from the actuating member through the second leaf spring being in a direction to move the rocker assembly away from the stop member to close the switch contacts, said actuating member during its return movement in the opposite direction engaging the second leaf spring and moving past said spring, the line of force from the actuating member through the spring on the return movement of the actuating member being in a direction to urge the rocker assembly against the stop member to maintain the open position of the contacts, a curved guide secured to said rocker assembly at a point spaced a substantial distance from the rocker pivot, said guide extending along said rocker towards the rocker pivot and curving away from the rocker, said second leaf spring extending between the rocker and guide and being biased against the curved portion of said guide.

CHARLES W. SEWELL. 

